Illuminant for electrical incandescent lamps.



0. M. THOWLBSS. ILLUMINANT FOR ELECTRICAL INGANDESGENT LAMPS.

APPLICATION FILED MAY 13| 1909..

n `Y Patented Feb. 28, 1911.

wvo wko z UNITED sTATEs PATENT oEEroE.

ORLANDO M. THOWLESS., OF NEWKABKrNEW JERSEY.

IVLIUMINANT ron ELEcfrarcAL INGANDESCENT LAMPS.

Specication of Letters Patent. Patented Feb, 28, 191 1.

Application led May 13, 1909. Serial No. 495,676.

To all whom it may concern:

Be it known that I, ORLANDO M. Tnownnss, a subject of theKing of Great Britain, residing at Newark, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Illuminants for Electrical Incandescent Lamps, of which the following is a specification.

My invention relates to a nevi.7 and improved illuminant for electrical incandescent lamps.

'The object of my invention is to provide an electrical incandescent lamp with an ill'uminant consisting of a body of material which is highly refractory, capable of giving a proper incandescent lighting effect in an economical manner and not expensive in its construction. To attain this object I form a rod or filament of the shape and size required, made chiefly of oxids of refracl tory n'letals, and by the method hereinafter set forth I cause a change to take placev in the composition of the rod or filament so that refractory conductive material is reduced from the oxid and incorporated with it to such an extent that a good conducting illuminant is obtained.

As an illustration of the method of .making my illuminant, I form a rod or filament (which for future reference I will term the glower) of a mixture of powderedv oxids of refractory Vmetals or of refractory metallic oxids or a mixture of one or more such oxids with a small quantity of flux and after properly shaping it I subject it to a very high temperature, such as the oxyhydrogen fiame until the particles forming,r the glower are fritted together into a vitrified condition. A mere mixing and baking will not produce a glower capable of carrying current when heated until its particles have been sweated or fused together so that the glower will present a vitrified appearf ance andbe very closely united into a solid structure. 4

The method, above described, will produce a glower which is normally a non-l cmiductor of electricity, but possesses the quality of becoming a good conductor when properly heated. It is then mounted and is ready for further operation. The next step is to reduce part of the metal, contained in the glower as'oxid, into metallic form, and this may be accomplished by placing the glower 1n a bell-jar or in a lamp-bulb, and

then transferring conductive material onto the glower from a filament or rod placed near it, which has already received a deposit of' conducting materialby the flashing process, or a suitable conductive substance may be used, capable of giving ofi' minute particles under the action of an electric current in an exhausted recelnacle. For instance, if conductive material such as carbid of silicon or carbid of boron be deposited, by flashing, on an electric-arc pencil,

or on an electrical incandescent filament, or 1t rods or str1 s of such substances are placed in a flas ing-jar or in a lamp-bulb l near to an oxid glower such as herein described, and an electric current caused to traverse the )encil or lament, raising itto a rather hig temperature in an exhausted chamber, the conductive material of the pencil or filament will be decomposed, and part of it will be ionized or vaporized into a mist of very minute particles, which will be deposited on the glower.. In case either carbid of silicon or carbid of boron is selected for the material to be ionized, ay deposit of silicon or boron or both, if both carbids are used, will be formed upon the glower, and this deposit serves as a conducting and heating medium, and as a reducer of metal held in oxid form in the "lower, The glowcr may then be mounted between terminals in the Well-known Way, excepting that great care must be taken in making a joint between the leading-in-Wi'es Iand the glower. Carbon cement 'is not a `very good material to use for this purpose, so it is better' to make the immediate connections between the glower and the leading-in-wires by means of tantalum Wire, on account of'its high melting point, but the leading-in-wires should be of platinum Where they are sealed to the glass stem of the lamp.

When the lower is properly connected in the lamplbul the latter is exhausted of air,

vand while still under the pumps action the glower is raised to quite a high temperature by means of an electric current traversing it. It will be found that the silicon deposit will act upon the oxid of the glower and' cause a reduction of metal therein, ,and by reason of the heat and the fineness of the silicon ions or particles, the reduced metal will be uniforml dissolved into, what is known as, solidy solution, for the oxid metal will not only be reduced on the survmixture of metal and oxid, but is a Another way of making my illuminant is` to prepare the oxid glow'er as previously deothers, or these latter may scribed, then mount it in a bell-jar or lampbulb and, after exhausting the air therefrom, bring into connection with the terminals an alternating current of say 500 volts pressure, when a cathodic discharge will occur in the receptacle, appearing first around each connecting wire and then gradually creeping along the glowcr from each terminal until the two glows meet, when the glowcr will become a conductor of electricity and be raised to a high temperature, the voltage will fall, and in this heated state oxygen will be given off which 'is pumped out as'it forms, so that metal will be reduced from the oxid.

The oxygen may in some instances be removed by mixing red phosphorus with wood alcohol, and placin it in the .stem of the lamp-bulb or in the ell-jar, as the case may be, and heating it, which causes it to change to yellow phosphorus. rlphis latter takes up oxygen as rapidly as it is given olf.

The oxid used for the glowcr may be such as thoria, zirconia, yttria, or one or more of these may be mixed with one or more of oxid of titanium, tantalum, tungsten, molybdenum, chromium, manganese, niobium or be used in any suit-able combination.

Instead of a solid glowcr a hollow one Figure l, a bell-jar, A, containing an oxid glowcr, B, having near it a filament, C, to be used for the ionizing of the. glowcr, B, holding-clamps for the glower are shown at D, D, while E, E, are similar clamps for holding the filament, C. The connecting wires leading to the clamps of the glowcr, B,-arc

glowcr shown as F, F, while those for the ionizing filament, C, are shown as G, G.

I show in Fig. 2, a completed lamp, wherein the lamp-bulb is shown as I-I, the finished illuminant as J, the immediate connecting wires as K, K, and the leading-in-wires as What I claim is:

1. In an electrical incandescent lampa current-carrying illuminant vitried throughout and conductive at ordinary temperatures.

2. In an electrical incandescent lamp an illuminant composed essentially of refractory conductive material and refractory oxid vitrified throughout. N

3. In an electrical incandescent lamp lan illuminant vitrited throughout and composed essentially of refractory metal and refractory oxid.

4. The method of making an illuminant for an electrical incandescent lamp which consists in forming a glower of oxids of refractory metals, raising the glowcr to a fritting temperature, exhausting the air, taking up the oxygen given off and reducing oxid material to produce suicient conductive material therein to allow a current to pass atordinary temperatures.

5. The method of converting a vitritied normally non-conductive oxid glowcr intoa conducting illuminant at ordinary temperatures which consists in reducing sufficient material within the glowcr to make it normally conductive'.

6. The method of making an illuminant for an electrical incandescent lamp which consists in forming a vitrified refractory oxid glowcr and thereafter reducing oxid therein to metal. v

7. The method of making an illuminant for an electrical incandescent lamp which consists in forming a vitriiied glowcr of f oxid of refractory metals and then causing Oxy gen to be given olf therefrom and oxid reduced therein to metal.

8. The method of making an illuminant for an electrical incandescent lamp which consists in heating a vitrified glowcr by means of a cathodic discharge and, when the glowcr becomes conductive, reducing oxid material therein to metal, thereby forming a normally conductive illuminant.

9. The method of making an illuminant for an electrical incandescent lamp which consists in heating a vitrified glowcr, formed of a mixture of oxids of refractory metals, maintaining the heat while the glowcr is under au air-exhausting action, reducing part of the material forming the glowcr and producing metal therein.

10. The method of transforming normal electrical non-conductive vitrificd glowers into conductorsl at ordinary temperatures suitable for illuminating purposes which consists in reducing part of the material exhausting action, reducing material therein 10 to metal throughout all parts of the glower and causing thereduced metal, to` unite in i solid solution with the unreduced material. In testimony whereof, I have signed my name tothis specification in the presence of two subscribing witnesses.

ORLANDO M. THOWLES S.

Witnesses: v

' J. HLCAMPBELL, ARTHUR J. THOWLEss. 

